Automatically detonated projectile



Nov. 20, 1945. 1 ANDERSON 2,389,288

AUTOMATI CALLY DETONATED PROJECT ILE Filed April 30, 1942 3nnentor Gttorneg 1 Patented Nov. 20, 1 945 s PATENT orslcs AUTOMATICALLY DETONATED PBOJECTILE Leslie J. Anderson, Indianapolis, Ind., asalgnor to Radio Corporation of America, a

of Delaware corporation Application April 30, 1942, Serial No. 441,081,

6 Claims.

cate, leading to considerable clifllculty in the design of satisfactory equipment. acoustically operated detonators are much more rugged and do not require the careful adjustment or delicate equipment common to the radio types.

It is an object of this invention to provide improved means for acoustically detonating a projectile in response to sound waves of predetermined frequency characteristics. Another object of the invention is to provide improved means for supporting the projectile in space for a considerable period of time to facilitate the formation of an efiective aerial barrage. Still another object is to provide improved means for equipping a projectile with a suitable parachute mecha, operable by a mechanism within the projectile, acoustically detonating the projectile by sound waves of predetermined frequency characteristics, and deenergizing the detonator mec M '1 o after a redetermined time interval. The invention will be described by reference to the of which Figure 1 is an elevational view of one embodiment of the invention, and i 1 2 is a schematic diagram of the detonator and timing mechanisms. Similar reference numerals are applied to similar elements throughout the Referring to Fig. 1, a projectile having an outer casing l is provided with a suitable explosive charge 2. A detonatort of the type utilizing a,

filament is disposed in proximity to the explosive charge 2. The projectile casing includes a hinged nose portion 5 connected to the base portion i by an invisible hinge 6. The nose portion is held in a closed position by the catch 9 including a notch it. A locking sear It contacts the latch t at the notch is to hold the nose portion in a closed position against the tension of the spring 8. It should be understood that any other suitable trigger operated latch mechanism may be utilized and that this invention is not to be limited to the precise mechanical details disclosed herein. A timing mechanism 4, which may be of any well mown type. and which should preferably be adjustable, both as to rate and initial operation, is suitably connected to the sear ill to release the latch 0 at a predetermined interval after the shell is fired. This interval should preferably be approximately the time required for the shell to reach the highest point in its trajectory. A suitably folded parachute 1 is enclosed within the hinged projectile nose 5, in such a manner that it will be released to support the projectile when the timing mechanism actuates the sear l0 and the spring 8 causes the projectile nose to open.

The detonating mechanism includes a comparatively large diaphragm ll connected in operable relation to a carbon, or other well known type,

microphone l2, proportioned and adapted to provide maximum output at some predetermined frequency, such as, for example, the sound produced by anairplane in flight.

Referring to Fig. 2, the timing mechanism t actuates a commutator, having a contact portion l1 and an insulated portion I8, to complete the circuit between one terminal of the microphone l2 and one terminal of the primary of the transformer id. The remaining terminal of the microphone l2 is connected to one terminal of a battery 13. The remaining terminal of the battery I3 is connected to the remaining terminal Of the primary of the transformer It. The detonator filament 3 is connected across the secondary of the transformer M. It will be apparent that the timing mechanism will not only release the parachute, as described heretofore, but will energize and deenergize the detonator mechanism, depending upon the relative position of the commutator contact section with the sliding contacts in connection therewith. By suitably adjusting the rate and phase of the timing mechanism and commutator, the detonator mechanism may be arranged to be responsive to sounds of predetermined frequency for the time interval beginning with the release of the parachute and ending at some predetermined altitude. with such an arrangement the projectile, if unexploded upon reaching the particular selected altitude, becomes insensitive to later received sounds and may be recovered for future use.

In operation, the resonant characteristics of the diaphragm ii, the microphone l2, and the transformer [4, may be determined by proportioning the physical dimensions and electrical design thereof lin any manner well known in the electrical or acoustics arts. Substantially no current will flow in the secondary of the transformer It when the meat in the transformer primary continuous. However, when sound waves, of i a frequency to which the diaphragm resonates,

2 applied to provide large amplitude vibration iation with an acoustic resonator, not shown, to

:rease its selectivity of frequency response. I claim as my invention:

1. A projectile including an explosive charge, V

ietonator for said charge, a timing mechanism, .d a parachute all enclosed within said projece, means responsive to predetermined operain of said timing mechanism for releasing said .rachute to support said projectile in space, eans disposed within said projectile for deriving .ergy in response to the impingement thereon sound waves, means for applying said energy said detonator for actuating said detonator, id means responsive to predetermined operation said timing mechanism and operable subselent to said release of said parachute for seleclely conditioning said sound responsive means 1d said energy applying means for actuating said etonator,

2. A device of the type described in claim 1 eluding means disposed in said projectile for :conditioning said sound responsive means and ,id energy applying means after a predetermined rne interval of said selective conditioning.

3. A projectile including an explosive charge, a

etonator for said charge, a timing mechanism, id a parachute all enclosed within said projecle, means responsive to predetermined operation 1' said timing mechanism for releasing said paraiute to support said projectile in space, resonant leans disposed within said projectile for deriving iergy in response to the impingement thereon of lund waves, means for applying said energy to Lid detonator for a tuating said detonator, and leans responsive to predetermined operation of rid timing mechanism and operable subsequent said release of said parachute for selectively )nditioning said sound responsive means and aid energy applying means for actuating said etonator.

4. A projectile including an explosive charge, a etonator for said charge, a timing mechanism,

and a parachute all enclosed within said projectile, means responsive to predetermined operation of said timing mechanism for releasing said parachute to support said projectile in space, means including a microphone disposed within said projectile for deriving energy in response to the impingement thereon of sound waves, means tor applying said energy to said detonator for actuating said detonator, and means responsive to predetermined operation of said timing mechanism and operable subsequent to said release of said parachute for selectively conditioning said sound responsive means and said energy app ying A means for actuating said detonator.

5. A projectile including an explosive charge. a detonator for said charge, a timing mechanism, and a parachute all enclosed within said projectile, means responsive to predetermined operation of said timing mechanism for releasing said parachute to support said projectile in space, means including a microphone having a diaphragm tuned to a predetermined frequency dis.-

posed within said projectile for deriving energy in response to the impingement thereonof sound waves, means for applying said energy to said detonator for actuating said detonator, and means responsive to predetermined operation of said timing mechanism and operable susbequent to-said release of said parachute for selectively conditioning said sound responsive means and said energy applying means for actuating said detonator,

6. A projectile including an explosive charge, a detonator for said charge, a timing mechanism, and a parachuteenclosed within said projectile, means responsive to predetermined operation of said timing mechanism for releasing said parachute to support said projectile in space, means including a circuit having predetermined frequency characteristics disposed within said projectile for deriving energy in response to the impingement thereon of sound waves, means for applying said energy to said detonator for actuating said detonator, and means responsive to predetermined operation of said timing mechanism and operable subsequent to said release'of said parachute for selectively conditioning said sound responsive means and energy applying means for actuating said detonator.

LESLIE}. ANDERSON. 

